<div style="margin-left: 50px;" id="imgs1"> 
<select name="" id="" style="margin-left: 15px";>
    <option value="">请选择大小</option>
    <option value="">大</option>
    <option value="">小</option>
</select><br><br>
<img src="./imgs/1.jpg" alt=""><br>
<button id="tbn" style="margin-left: 30px;" onclick="touzi">开始</button>
</div>
<script type="text/javascript">
var tupian=document.getElementById('imgs1');
var anniu=document.getElementById('tbn');

function touzi()
{
    var myInerterval=setInterval(function(){
    var img_list=['./imgs/1.jpg','./imgs/2.jpg','./imgs/3.jpg','./imgs/4.jpg','./imgs/5.jpg','./imgs/6.jpg'];
    var num=Math.floor(Math.random()*img_list.length);
			touzi.src=img_list[num];
    
    },300)
}
    
</script>